1. Field of the Invention
The present invention relates to a flat display device and, more particularly, to a flat display device used as an image display for use in computer, television, and the like.
2. Description of the Prior Art
The plasma display panel (referred to as PDP hereinafter) as a flat display device has been put into practical use of a display device such as a wall hanging television set. PDPs are classified into AC type and DC type according to difference in voltage drive system. In most cases, a display portion of an AC type color PDP has a structure shown in FIG. 1, for example.
In FIG. 1, address electrodes 102 and a fluorescent layer for covering these address electrodes 102 are formed on a back glass substrate 101. A dielectric layer 105, a pair of display electrodes 106, 107, a protection layer 108, etc. are formed on a front glass substrate 104 opposing to the back glass substrate 101. In addition, a gas is sealed into a discharge space 109 between the front glass substrate 104 and the back glass substrate 101.
In practical use of such PDP, lifetime of the panel, operating voltage, emission luminance, chromatic purity and so on are to be considered as important evaluation factors. These evaluation factors are significantly affected by gas mixture which is sealed into the discharge space 109.
Various investigations about such gas mixture have been performed. By using two component gas mixture consisting of neon (Ne) and xenon (Xe), or helium (He) and xenon, otherwise three component gas mixture consisting of helium, argon (Ar) and xenon, or neon, argon and xenon, such PDPs having long lifetime, low operating voltage, and in addition sufficient luminous brightness are going to be achieved.
Lights having wavelength other than visible ray, e.g., near infrared rays are emitted from PDPs using such gas mixture.
Such facts have been made clear by the inventors of the present invention that there are possibilities that such near infrared rays cause a harmful influence on transmission of infrared data in the POS (point of sales) computer information system used in the location where PDP is established, or cause malfunction of near infrared remote control for domestic electric appliances in the home where PDP is used as the television set.
These facts have been known until now, and they have been found at first by the inventors of the present invention.